One of the summer's best treats is fresh berries. But they go bad so quickly that you really have to be on your toes not to lose a great batch of strawberries or blueberries. Harold McGee of The New York Times. was tired of his berries going bad practically overnight, so he investigated the concept of using heat or Thermotherapy to make the fruit last longer.
I gathered a dozen or so reports that hot-water treatments suppress mold growth on berries, grapes and stone fruits. The test temperatures ranged from 113 to 145 degrees, with exposure times of a few minutes at the lower temperatures, and 12 seconds at the highest.
I found it hard to believe that any part of a plant could tolerate 145-degree water. My finger in the same water would get a third-degree burn in less than 5 seconds, and eventually reach medium rare.
I bought pints of various berries, divided each batch into two samples, and heated one by immersing and swishing its plastic basket in a pot of hot water. I emptied the heated sample onto towels to cool down and dry. Then I repacked it, and encouraged both baskets to spoil by wrapping them airtight and letting them sweat on the kitchen counter. After 24 hours I counted the moldy berries in each basket.
The strawberries fared best when I heated them at 125 degrees for 30 seconds. In two samples from different sources, this treatment gave a total of 1 moldy berry out of 30, where the untreated baskets had 14. I also treated some bruised berries, including one with a moldy tip. After 24 hours none were moldy. The tip mold not only hadn’t spread, it had disappeared.
If you don't feel up to performing Harold's amazing thermotherapy on your fruits, he says you should at least spread out your fruit and dry it off when you get it home. Moisture causes mold growth. Then put the fruit in the refrigerator to slow down the mold process. In any event, the entire article is a most interesting read.
